Analog storage mechanism



April 1958 E. M. CHRISTENSEN 2,830,762

ANALOG STORAGE MECHANISM Filed March 1, 1956 FIG. I

INVENTOR.

ELMEE M CHEISTENSEA/ United States Patent 9 ANALOG STORAGE MECHANISM Elmer M. Christensen, Cambridge, Mass, assignor to General Mills, Inc., a corporation of Delaware Application March 1, 1956, Serial No. 563,797

4 Claims. (Cl. 235-91) This invention relates generally to drive mechanisms and pertains more particularly to an analog storage mechanism capable of storing various degrees of input shaft rotations while an output shaft is temporarily held stationary.

One object of the invention is to store the rotation imparted to a drive shaft while the driven shaft is held stationary so that a driven device may be properly operated without losing the information currently being fed to the drive shaft. In this regard it is intended to utilize aform of spring action in such a way that a predetermined amount of drive shaft rotation can be stored during, for example, the time that it takes to make a static reading of a counter or to make a printed record thereof.

Another object of the invention is to provide an analog storage mechanism that will accurately store the information during the stopping operation and which information will be fully recovered after stoppage so that no errors are introduced in the system. More particularly, the invention envisages a preloading of the springs of which the mechanism is comprised, which preloading is instrumental in assuring an accurate repositioning of the output shaft once the shaft has been released.

A further object of the invention is to provide a mechanism of the foregoing character which is capable of acting in either rotative direction. I

Yet another object of the invention resides in the provision of mechanism by which almost two complete revolutions of the drive shaft may be stored during stoppage of the driven shaft.

Still further, it is within the contemplation of the invention to provide a drive mechanism capable of carrying out the foregoing aims which will be rugged and longiasting, requiring little or no maintenace.

Other objects will be in part obvious, and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawing:

Figure 1 is an elevational view, partly schematic in nature, which shows one use to which the invention may be put;

Fig. 2 is an end view of the analog storage mechanism;

Fig. 3 is a sectional view taken in the direction of line 3-3 of Fig. 2;

Fig. 4 is a sectional view somewhat angularly spaced from Fig. 3 taken in the direction of line 4-4 of Fig. 2; and

Fig. 5 is an exploded perspective view of the storage mechanism illustrating in more detail the various configurations of the parts making up this storage mechanism.

Referring now in detail to the drawing, it is to be observed that the storage mechanism has been generally designated by the reference numeral 10. in order to appreciate fully the benefits to be derived from the mech- "ice anism 10, a system wherein the mechanism will find especial utility will first be described before going into detail as to the specific construction of the parts making up the mechanism 10. Accordingly, it is to be observed from Fig. 1 that the system may include an input or drive shaft 12 coupled to the mechanism 10 and the system further includes an output or driven shaft 14. The driven shaft 14 is equipped with a gear 18 which is en meshed with two driven gears 20 and 22. The driven gear 20 is directly connected to a shaft 24 which is in turn coupled to a counting device 25. The counting device 25 may be of conventional construction and need not be further elaborated upon other than to say that it is equipped with a plurality of number wheels 26. By reason of rotation imparted to the shaft 24 the number wheels 26 will register the total number of revolutions of the shaft 24 and of course the shaft 24 rotates in direct proportion to the input shaft 12 so that an accurate determination of the number of revolutions of the shaft 12 may be obtained.

Also included in the system depicted in Fig. l is another shaft 28, this shaft being directly connected to the driven gear 22 and having at its other end a gear 30 by way of which a printing device 32 may be rotatively indexed. Here again, the device 32, like the earlier de-- scribed device 24, is equipped with a plurality of rotatable wheels 34. However, in this instance, the wheels 34 are capable of performing a printing operation, these wheels being of rubber or metal or other material having the appropriate numerical type embossed thereon.

The printing device 32 also has included as a part thereof a bed plate 36 upon which a card or tape 38 rests, which card or tape receives the printing from the number wheels 34 either by ink applied to said wheels or by a type ribbon or carbon paper thereunder. The bed 36 is disposed for vertical reciprocation by a pair of guide rods 46 having circumposed thereabout springs 42, which springs act in a direction to urge normally the bed plate 36 in a downward direction relatively to the fixedly located device 32. For the purpose of overcoming the action of the springs 42, there is located subjacently the 'bed plate 36 a solenoid 44 having its armature 46 connected to the underside of the bed plate. When the solenoid 44 is energized the armature 46 is moved upwardly so that the springs 42 are overcome and the type on the printing wheels 34 then contacts the card or tape 38.

From the foregoing it can be appreciated, it is believed, that if the printing wheels 34 are rotating at the time that the solenoid 44 is-energized, then a clear-cut printing can not be achieved. Therefore, it is extremely desirable in order to produce a legible record to have the number wheels 34 stationary while a printing operation is taking place. To this end the bed plate 36 is provided with an upstanding pawl element 48 which is engageable with a star wheel 50 mounted on the driven shaft 14. Hence when the solenoid 44 is energized, not only does the printing operation take place but concurrently therewith the driven shaft 14 is stopped so that there is no further movement of the printing wheels 34 and consequently a clearly readable record is produced on the card or tape 38.

Describing now the specific construction of the storage mechanism It) by which the above-alluded to stoppage can be achieved without loss of information being supplied via the input shaft 12, it will be observed that the mechanism 10 comprises a pair of axially spaced discs 52a and 52b. These rotatable discs 52a and 52b are respectively equipped with hubs 54a and 54b. Rotation of the drive shaft 12 and the hub 54a is by reason of a transverse pin 56a and rotation of the hub 54b is in turn transmitted to the driven shaft 14 by means of a second pin 56b. A floating shaft 58 is journaled for rotation in the hubs 54a and 54b. Carried by the floating shaft 58 is an intermediate disc or housing 60 having a peripheral flange or rim 62 forming recesses for the housing of a pair of coiled flat springs 64a and64b. The outer ends of these springs 64:; and 64b are received in notches 66a and 66b in the rim 62 whereas the opposite or inner ends of the springs are similarly accommodated in notches 68a and 68b disposed in the hubs 54a and 54b.

The mechanism further includes a pair of axially directed pins 70a and 70b mounted in radial portions of the discs 52a and 52b. These pins 70a and 70b are respectively engageable with a pair of rotatable arms 72a and 72b having thereon ring portions 74a and 74b which loosely circumscribe the hubs 54a and 5412. Stop elements in the .form of projections 76a and 76b are also engageable by the arms 72a and 72b inasmuch as the arms are of sufficient radial length so as to engage both the pins 70a and 70b as well as the more radially displaced stops 76a and 76b.

As hereinbefore indicated, it is possible to preload the springs 64a and 64b so as to produce an accurate transmission of power between the shafts 12 and 14. By preloading the springs 64a and 64b, thetorque required in driving the output shaft 14 is adequately compensated for. More specifically, it may be explained that the devices 25 and 32 quite obviously require a certain amount of driving force for their operation and by preloading the springs so that the springs do not have to be flexed in order to transmit this amount of driving force, there is eliminated the degree of rotation of the drive shaft thatotherwise would be necessary in winding up one spring in order to rotate the output shaft 14 so as to supply the necessary take-up force that would be needed in rotating the two devices 25 and 32. As long as the sum of the friction, holding, inertia and other rotational forces does not exceed the preload of the particular spring being wound, a stable position is accurately maintained.

Referring now to the manner in which the aforementioned preloading is obtained, reference should be had to Figs. 2 and 4. If we assume that Fig. 2 is an end view of Fig. 4 taken from the right side, it can readily be appreciated that by rotating the disc 52a sufliciently counterclockwise so that the pin 70a assumes its angular position shown in Fig. 2, there will have been imparted to the spring 64a a certain amount of distortion. This distortion or flexing of the spring 64a is retained by way. of the arm 72a which is interposed between the pin 70a and the stop 76a integral with rim 62 of the intermediate disc 60. If the other pin 7% is rotated in the same direction, which is, of course, opposing any tendency for the pin 70:: to return to its free position, then a preloading of the spring 64b will be obtained. Actually, the degree of preloading will be determined by the amount of load to which the driven shaft 14 is subjected and with this in mind, it can readily be appreciated that the pins 70a and 70b need not be fixedly located on the two axially spaced discs 52a and 52b until the requisite amount of preloading has been imparted to the springs 64a and 64b. This location of the pins 70a and 70b may be readily obtained by postponing the drilling of, the apertures in which they are received until the desired amount of preloading has been ascertained. At any rate, the locating of the pins 70a and 70b is instrumental in retaining the desired amount of preloading. However, if desired, the springs 64a, 6419 may be replaced with springs having different spring constants in order to vary the preloading.

Having explained how the preloading of the springs 64a and 64b is determined, it is felt that the operation of the device will be readily apparent. However, a brief outline of what transpires will unquestionably be of help in producing a facile understanding of the merits involved in the use of the exemplified analog storage mechanism labelled it We will therefore assume that the input or drive shaft 12 is supplying analog information to the mechanism 10. This information is to be transmitted to both the counting device 24 and the printing device 32. However, in order to produce a good record of the number of revolutions produced by input shaft 12 it is necessary to stop the driven shaft 14 while the printing operation is taking place. As already mentioned, this is accomplished by engaging the pawl 48 with the star wheel 50 through the medium of the solenoid 44.

The point to be stressed here is that while the stoppage of the star wheel is taking place, intelligence or information is still being imparted to the drive shaft 12 and this information must be stored for subsequent release if the next printing operation is to be acorrect one. In this regard, it will be remembered that the preloading of the spring 64a was in a counterclockwise direction when viewed from the right in Fig. 4. If we now assume that the input or drive shaft 12 is rotating counterclockwise and the output shaft 14: is held'stationary, the disc 52a will be so rotated that the pin 70a will move away from the arm 72a and will rotate substantially a full revolution before itengages the opposite side of this arm 72a. Once this has occurred, then the pin 70a will continue to rotate in the same directionbut will cause the arm 72a to move therewith. The arm 72a can therefore move almost a complete revolution before it engages the opposite side of the stop 76a. It is the engagement of the opposite side of the stop 76a that causes a direct mechanical drive to then be produced. Consequently it can be seen thatt here is introduceda storage of almost two complete revolutions of the drive shaft 12, being less than two revolutions by only the width of the arm 72 and the width of the stop 76a. All the while that this is taking place, the spring 64a is being wound up inasmuch as the shaft 14 is being held-stationary by virtue of the energization of the solenoid 44. Of course, during this period the stop 76b attempts to rotate, but its rotational tendency is restrained by the arm 72b and the pin 70b, the latter being unable to move owing to its location on the now stationary disc 52b. When the solenoid 44 is deenergized, then the springl64a releases its stored energy, unwinding itself, and this unwinding action is transmitted via the intermediate disc 60 through the stop 76b, arm 72b, and pin 70b to the disc 52b.

On the other hand, if the rotation of the shaft 12 should be in the opposite direction, then the stop 76b moves in a direction away from its arm 72b and winds up this latter spring 64b. By the same token, then, release of the shaft 14 by reason of the deenergization of the solenoid 44 will cause thespring 64b to unwind itself and advance the number wheels 26 and the printing wheels 34 to the correct position that they would have been-rotated to if the stopping action had not beenintroduced.

From the foregoing operational sequence it is believed quite apparent that the shaft 12 may rotate in either direction and the particular direction in which this shaft rotates determines which spring 64a and 64b is to become operative as far as storing energy therein is concerned. Further, it will be manifest that the shaft 12 may rotate almost two full revolutions before a directmechanical driveis inaugurated, therebyleaving ample timeforthe printing operation to take place.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all-matter contained in the above description or shown in the accompanying draw ings shall be interpreted as illustrative and not in a limiting sense.

It is also to he understood that the language used in thefollowing claims is intended to cover all of the generic and specific features of the invention herein described and matter. of language,.might be said to fall therebetween.

What is claimed is:

1. An analog storage mechanism comprising a drive shaft, a driven shaft and an intermediate member mounted for relative rotation between said shafts, a first spring connecting the drive shaft to said intermediate member, a second spring connecting said intermediate member to said driven shaft, and means for preloading each of said springs, said preloading means including a stop element on each side of said intermediate member, a stop element offset from the axis of rotation of each shaft and rotatable in unison with its associated shaft, and an arm on each side of said intermediate member, each arm being engageable with one of said intermediate stop elements and the stop element associated with the shaft on that side.

2. An analog storage mechanism comprising first, second and third relatively rotatable discs, a first spring connecting the first disc to the second, a second spring connecting the second disc to the third, an axial projection on each side of said second disc at one radius, an axial projection on each of said first and third discs at a lesser radius than the projections on said second disc, a rotatable arm intermediate the first and second discs, and a rotatable arm intermediate the second and third discs, said first arm being of sufi'icient length so as to be engageable by the projection on said first disc and the adjacent projection on said second disc and said second arm being of suflicient length so as to be engageable by the projection on said third disc and the other projection on said second disc, whereby a selected rotation of said first and third discs in one direction will preload said springs, engagement of the projections on said first and third discs with their associated arms and engagement of said arms in turn with the projections on said second disc maintaining a preloaded spring relationship.

3. An analog storage mechanism comprising a pair of discs each having a hub connected with a shaft for rotation therewith, a third disc between said pair of discs journaled for relative rotation With respect thereto, said third disc having a projection on either side at a location radially spaced from its center of rotation, a coil spring on each side of the third disc having one end anchored to said third disc and its other end anchored to one of said pair of discs, respectively, an arm associated with each of said pair of discs having a portion thereof freely encircling the hub of that particular disc, a projection on each of said pair of discs engageable with one of the arms, whereby said coil springs may each be preloaded by flexing said springs and having said arms normally engage the projections on said pair of discs and on said third disc in the flexed condition of said springs.

4. An analog storage mechanism in accordance with claim 3 in which the projections on said third disc are located at a greater radius from the center of rotation than are the projections on said pair of discs, whereby rotation of one of said pair of discs can occur While the other of said pair of discs is held stationary.

References Cited in the file of this patent UNITED STATES PATENTS 773,320 Haase -c Oct. 25, 1904 2,336,307 Slye Dec. 7, 1943 2,722,379 Hayek Nov. 1, 1955 2,746,318 Benjamin May 22, 1956 

